More on this book
Community
Kindle Notes & Highlights
Affordances determine what actions are possible. Signifiers communicate where the action should take place. We need both.
Visceral responses are fast and completely subconscious. They are sensitive only to the current state of things. Most scientists do not call these emotions: they are precursors to emotion.
Eliminate all error messages from electronic or computer systems. Instead, provide help and guidance. •
Eliminate the term human error. Instead, talk about communication and interaction: what we call an error is usually bad communication or interaction. When people collaborate with one another, the word error is never used to characterize another person’s utterance. That’s because each person is trying to understand and respond to the other, and when something is not understood or seems inappropriate, it is questioned, clarified, and the collaboration continues. Why can’t the interaction between a person and a machine be thought of as collaboration?
It is easy to design devices that work well when everything goes as planned. The hard and necessary part of design is to make things work well even when things do not go as planned.
Best mapping: Controls are mounted directly on the item to be controlled. • Second-best mapping: Controls are as close as possible to the object to be controlled. • Third-best mapping: Controls are arranged in the same spatial configuration as the objects to be controlled.
Note that a superior solution would be to solve the fundamental need—solving the root need. After all, we don’t really care about keys and locks: what we need is some way of ensuring that only authorized people can get access to whatever is being locked. Instead of redoing the shapes of physical keys, make them irrelevant.
Designers need to avoid procedures that have identical opening steps but then diverge. The more experienced the workers, the more likely they are to fall prey to capture.
The immediate cause of most memory-lapse failures is interruptions, events that intervene between the time an action is decided upon and the time it is completed. Quite often the interference comes from the machines we are using: the many steps required between the start and finish of the operations can overload the capacity of short-term or working memory.
Action slips are relatively easy to detect because it is usually easy to notice a discrepancy between the intended act and the one that got performed. But this detection can only take place if there is feedback. If the result of the action is not visible, how can the error be detected?
Mistakes often arise from ambiguous or unclear information about the current state of a system, the lack of a good conceptual model, and inappropriate procedures.
Difficulties arise when we do not think of people and machines as collaborative systems, but assign whatever tasks can be automated to the machines and leave the rest to people. This ends up requiring people to behave in machine like fashion, in ways that differ from human capabilities. We expect people to monitor machines, which means keeping alert for long periods, something we are bad at. We require people to do repeated operations with the extreme precision and accuracy required by machines, again something we are not good at. When we divide up the machine and human components of a task in
...more
What we call “human error” is often simply a human action that is inappropriate for the needs of technology.
Assume that every possible mishap will happen, so protect against them. Make actions reversible; make errors less costly.
Put the knowledge required to operate the technology in the world. Don’t require that all the knowledge must be in the head. Allow for efficient operation when people have learned all the requirements, when they are experts who can perform without the knowledge in the world, but make it possible for non-experts to use the knowledge in the world. This will also help experts who need to perform a rare, infrequently performed operation or return to the technology after a prolonged absence. • Use the power of natural and artificial constraints: physical, logical, semantic, and cultural.
...more
The first phase is to find the right problem, the second is to find the right solution.
In theory, there is no difference between theory and practice. In practice, there is.
Because the fundamental principles of designing for people are the same across all domains. People are the same, and so the design principles are the same.
Design must take into account sales and marketing, servicing and help desks, engineering and manufacturing, costs and schedules.
